You have a duty to allow your children to have contact with their father.
The fact you don't like the travel and want to get rid of your car are moot points really.
The reality is you want to make choices to your personal benefit that infringe on your Ex in terms of both the cost and time the travel. Put simply you want him to subsidise your choices.
I obviously don't know the back story and it's quite possible in the wider context that your not being as unreasonable as your appear in this instance.
However, you've made a unilateral demand to him to pick up the children and are now upset that he's done exactly the same as you in return.
Successful co-parenting is about putting your responsibilities to the children first and affording your Ex courtesy and respect whilst they do so.
If you want to get rid of your car then you need to consider how you can still meet your obligations or find an alternative (compromise in other words) that means your ex is happy with the new arrangement. That might mean less maintenance for you and/or more time with the children for him.
As stands - on this issue - you are not co-parenting. You were blackmailing him by saying "if you don't pick up the kids they aren't coming because I'm not going to facilitate contact".
You are then put out when he's shown you exactly how that must feel....
Honestly you need to take a step back from this and think about a better way to approach this issue.